LOANS AND LEASES (Loans And Leases, Net Of Unearned Income By Segment, Class And Geographical Location) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Real estate [Abstract]
Total	$ 9,726,970	$ 9,712,936
Loan concentrations [Abstract]
Maximum percentage of loan concentrations (in hundredths)	10.00%
Alabama and Florida Panhandle [Member]
Real estate [Abstract]
Total	1,089,591
Arkansas [Member]
Real estate [Abstract]
Total	1,244,540
Louisiana [Member]
Real estate [Abstract]
Total	1,036,083
Mississippi [Member]
Real estate [Abstract]
Total	3,159,975
Missouri [Member]
Real estate [Abstract]
Total	454,752
Tennessee [Member]
Real estate [Abstract]
Total	1,030,513
Texas [Member]
Real estate [Abstract]
Total	1,250,161
Other
Real estate [Abstract]
Total	461,355
Commercial And Industrial [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	1,676,366
Real estate [Abstract]
Total	1,676,366	1,746,486
Commercial And Industrial [Member] \| Alabama and Florida Panhandle [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	189,823
Commercial And Industrial [Member] \| Arkansas [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	208,990
Commercial And Industrial [Member] \| Louisiana [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	217,749
Commercial And Industrial [Member] \| Mississippi [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	555,594
Commercial And Industrial [Member] \| Missouri [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	77,274
Commercial And Industrial [Member] \| Tennessee [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	135,672
Commercial And Industrial [Member] \| Texas [Member]
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	267,825
Commercial And Industrial [Member] \| Other
Loans and leases, net of unearned income [Abstract]
Commercial and industrial	23,439
Real Estate [Member]
Real estate [Abstract]
Consumer mortgages	2,301,112
Home equity	538,042
Agricultural	236,898
Commercial and industrial-owner occupied	1,518,153
Construction, acquisition and development	892,730
Commercial real estate	1,993,473
Real Estate [Member] \| Alabama and Florida Panhandle [Member]
Real estate [Abstract]
Consumer mortgages	195,923
Home equity	74,805
Agricultural	6,515
Commercial and industrial-owner occupied	176,298
Construction, acquisition and development	128,479
Commercial real estate	288,445
Real Estate [Member] \| Arkansas [Member]
Real estate [Abstract]
Consumer mortgages	286,833
Home equity	37,890
Agricultural	71,542
Commercial and industrial-owner occupied	175,152
Construction, acquisition and development	91,070
Commercial real estate	336,170
Real Estate [Member] \| Louisiana [Member]
Real estate [Abstract]
Consumer mortgages	193,390
Home equity	56,275
Agricultural	29,253
Commercial and industrial-owner occupied	177,340
Construction, acquisition and development	87,238
Commercial real estate	247,765
Real Estate [Member] \| Mississippi [Member]
Real estate [Abstract]
Consumer mortgages	774,883
Home equity	212,510
Agricultural	70,036
Commercial and industrial-owner occupied	572,800
Construction, acquisition and development	287,700
Commercial real estate	486,219
Real Estate [Member] \| Missouri [Member]
Real estate [Abstract]
Consumer mortgages	68,048
Home equity	21,507
Agricultural	2,725
Commercial and industrial-owner occupied	58,596
Construction, acquisition and development	22,758
Commercial real estate	201,241
Real Estate [Member] \| Tennessee [Member]
Real estate [Abstract]
Consumer mortgages	239,586
Home equity	125,541
Agricultural	12,567
Commercial and industrial-owner occupied	158,062
Construction, acquisition and development	141,940
Commercial real estate	179,111
Real Estate [Member] \| Texas [Member]
Real estate [Abstract]
Consumer mortgages	374,743
Home equity	8,063
Agricultural	44,260
Commercial and industrial-owner occupied	199,905
Construction, acquisition and development	113,706
Commercial real estate	204,190
Real Estate [Member] \| Other
Real estate [Abstract]
Consumer mortgages	167,706
Home equity	1,451
Construction, acquisition and development	19,839
Commercial real estate	50,332
Credit Cards [Member]
Real estate [Abstract]
Credit cards	106,287
Total	106,287	113,426
Credit Cards [Member] \| Other
Real estate [Abstract]
Credit cards	106,287
All Other [Member]
Real estate [Abstract]
All other	463,909
Total	463,909	486,172
All Other [Member] \| Alabama and Florida Panhandle [Member]
Real estate [Abstract]
All other	29,303
All Other [Member] \| Arkansas [Member]
Real estate [Abstract]
All other	36,893
All Other [Member] \| Louisiana [Member]
Real estate [Abstract]
All other	27,073
All Other [Member] \| Mississippi [Member]
Real estate [Abstract]
All other	200,233
All Other [Member] \| Missouri [Member]
Real estate [Abstract]
All other	2,603
All Other [Member] \| Tennessee [Member]
Real estate [Abstract]
All other	38,034
All Other [Member] \| Texas [Member]
Real estate [Abstract]
All other	37,469
All Other [Member] \| Other
Real estate [Abstract]
All other	$ 92,301

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Reflects the net carrying amount of agricultural real estate loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

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- Definition

Reflects the net carrying amount of commercial and industrial-owner occupied real estate loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

No definition available.

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- Definition

Reflects the net carrying amount of commercial real estate loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

No definition available.

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- Definition

Reflects the net carrying amount of construction, acquisition and development real estate loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

No definition available.

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- Definition

Reflects the net carrying amount of consumer mortgage real estate loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

No definition available.

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- Definition

Reflects the net carrying amount of home equity real estate loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

No definition available.

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- Definition

The maximum percentage of loan concentrations that comprise the aggregate total of all loans, for any particular class.

+ References

No definition available.

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Reflects the net carrying amount of commercial loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on commercial loans and leases.

+ References

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Reflects the net carrying amount of consumer loans and leases held in portfolio, after deducting deferred income, but before deducting the allowance for losses on consumer loans and leases.

+ References

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5074-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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Reflects the net carrying amount of loans and leases held in portfolio, not otherwise defined in the taxonomy, after deducting deferred income, but before deducting the allowance for losses on such loans and leases.

+ References

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